You go on a first date Tuesday night, and you think it went pretty well.

In fact, you’re sure it went pretty well. I mean, why else would your prospective new sweetheart constantly let his or her knee graze yours or share your drink as if you’d known each other for more than, oh, 45 minutes?

You go home content, and maybe even happy.

Then, Wednesday morning comes and goes, and by Wednesday at around 3 p.m., you think the potential new relationship is doomed.

With the advent of modern technology — texting, Snapchat, e-mail, Facebook — so many relationships end before they even start because no one knows the answer to the simple question: How soon do you follow up after a date?

The antiquated “three-day rule” before you respond with a “Thank you” or an “I’d like to see you again” no longer applies.

A few years ago, a survey performed by the company LoveGeist was commissioned by, and it found that after a first date on a Saturday evening, most daters will get in touch by 11:48 a.m. on Monday with a call or text.

Thus, 1.52 days is now the average time spent waiting for a follow-up message. Most people assume that if their date was interested in meeting again, there will be some imminent communication.

(For what it’s worth, I don’t recommend a first date on a Saturday night, especially a first date that was arranged online. A weeknight or Sunday evening date works better. Then, if you want to see each other again, you can plan for the coveted Friday or Saturday night slot when you already know you have some chemistry.)

In this day and age, we are all surgically attached to our phones. When it comes down to it, if you like someone, it’s so easy to get in touch. If you wait the antiquated three days, it’s already a foregone conclusion that you’re probably just not that into the other person.

So, here are the new rules to dating response: If you like someone and want to make plans for a second date, then make the contact in a timely fashion.

A short and sweet text saying, “Had a great time last night! Would love to do it again if you’re interested. Let me know what your week looks like.”

And ladies, if he has the courtesy to ask you out again and you’re not interested, do the kind thing and thank him, using the honest answer that you didn’t feel a spark. Ignoring an invitation will only make a possible future encounter (remember, it’s a small world) that much more awkward.

No ghosting. Period.

Somehow the “1.52-day rule” just doesn’t quite have the same ring to it. Perhaps we’ll just call it the “36-hour rule.” Now, that’s kind of catchy.